The Origin and Ecology of a Likely Introduced Population of Southern Black-Bellied Salamanders (Desmognathus amphileucus)

Characterizing the origin and ecology of introduced species is important for developing management plans. We discovered an isolated population of black-bellied salamanders (Desmognathus sp.) in the Piedmont of Georgia, 30 km southwest of their known range. We used phylogenetic methods to confirm the salamanders were Southern Black-Bellied Salamanders (D. amphileucus), with their closest relatives in the Blue Ridge. We observed all life stages and used mark-recapture methods to estimate a population size of 39 post-metamorphic individuals. We used gastric lavage to document prey items novel in diet studies of black-bellied salamanders but reported previously in other Desmognathus. We hypothesize this population was likely introduced via the bait trade, has grown since introduction, and is consuming resources used by native salamanders.

明确外来物种的起源与生态特征，对制定物种管理方案具有重要意义。本研究在佐治亚州皮德蒙特地区发现了一处孤立的黑腹蝾螈（black-bellied salamanders，*Desmognathus* sp.）种群，该区域距离其已知分布范围西南约30公里。研究人员通过系统发育分析方法确认，该种群为南方黑腹蝾螈（Southern Black-Bellied Salamanders，*D. amphileucus*），其近缘类群分布于蓝岭山脉。本研究观测到了该种群的所有生活史阶段，并采用标志重捕法（mark-recapture methods）估算得到，其变态后个体总数为39只。研究人员通过胃灌洗法（gastric lavage）记录到了黑腹蝾螈饮食研究中未见报道的猎物类群，但此类猎物此前在其他无肺螈属（Desmognathus）物种的食谱中已有记录。本研究推测，该种群极可能通过饵料贸易被引入，自引入以来种群规模持续扩张，并正在取食本土蝾螈所利用的食物资源。